Piston



E. KOTTUSCH April 1, 1930.

PISTON Filed June 15, 1928 atkmmu Patented Apr. 1, 1930 UNITED STATES EMIL KOTTUSCH, OF

DETROIT, MICHIGAN PISTON Application filed. June 15,

This invention relates to pistons for internal combustion engines, and more particularly to such pistons having skirt portions to yieldingly engage the cylinder wall for the purpose of guiding the piston in its movement and preventing piston slack.

The object of the present invention is to provide a construction whereby pistons may be cheaply, accurately and facially formed with yieldable portions at opposite sides of the piston to engage the cylinder walls yieldingly and prevent piston slack, at the same time providing for piston clearance within the cylinder to take care of uneven expansion 3 and to permit the use of a piston of considerably less diameter than the diameter of the cylinder. A further object is to provide a construction having certain other new and useful features, all as hereinafter more fully set forth.

With the above and other ends in view the invention resides in the construction and arrangement hereinafter more fully set forth.

With the above and other ends in view the invention resides in the construction and arrangement hereinafter more fully described and more particularly pointed out in the appended claims reference being had to the accompanying drawing in which Figure 1 is a side elevation of a piston illustrative of an embodiment of the present invention;

Figure 2 is a transverse vertical section through the same;

Figure 3 is an end elevation; and

Figure 4 is a transverse section substantially upon the line 44 of Figure 2.

It is necessary to make the piston of an internal combustion engine of considerably less diameter than the diameter of the cylinder bore in order to provide for the difference in expansion between piston and cylinder, and this is more necessary where the piston 1s formed of a metal havlng a greater co-eflicient 45 of expansion than that of the metal from which the cylinder is formed, such as aluminum alloys now commonly used in piston construction. Where there is considerable difference in diameters of piston and cylinder bore, when the engine is first started and be- 1928. Serial No. 285,548.

fore the piston becomes heated and thereby expanded, the piston is loose in its cylinder and the angularity of thrust of the connecting rod causes this piston to move at its lower end from side to side of the cylinder, causing what is known as piston slack.

In order to prevent piston slack various means has been provided for yieldingly en gaging the piston wall and in the present construction it is proposed to form the skirt por tion 1 of the piston with yielding portions or tongues 2. The head 3 of the piston is formed in the usual manner with piston ring grooves 4.

The tongues 2 are formed by slitting or sawing through the wall of the skirt 1 along lines 5 extending transversely of the piston at each side of the bearings 6 which are provided on opposite sides of the skirt to receive the usual connecting rod pin which pivotally attaches the connecting rod to the piston, said pin and connecting rod not being shown in the present drawings. The cuts or slits 5 are connected together at one end by a longitudinal cut or slit 7, thus severing a portion of the skirt at each sideof the bearing boss 6 and forming the tongues 2 which are integral with the skirt at one end.

In order that the free end of these tongues may have an outward yielding action, that is n so that they will project slightly outward beyond the face of the skirt, in forming the piston these tongues are out from the piston skirt before the skirt is finally ground or turned to the proper diameter and the free ends of the tongues are then forced inwardly the desired amount to provide for the outward projection of these free ends when the piston is finished.

In order that the free ends of the tongues 2 may be held after being depressed inwardly, each tongue is formed in the castingv of the piston with an inward projection and this inward projection is cut through horizontally by'the slits 5 so that adjacent the free end of each tongue an ear 8 is formed and a like ear 9 is provided in mating relation thereto on the lower portion of the skirt.

The piston is then placed within a suitable chuck which will depress the free ends of the tongues inwardly and then the several ears 8 and 9 and the portion 10 of the piston head adjacent the upper side of the tongue is bored to receive a pin 11. When this pin is in place, the free ends of the tongues are held thereby in depressed condition and the exterior surface of the skirt of the piston is then turned or otherwise liirmed to the exact desired diameter. After being so termed to the proper diameter, the pins 11 are removed, thus releasing the free ends of the tongues which will spring outwardly as clearly illustrated in Figure 3, thereby providing yielding projections at opposite sides of the piston skirt to engage the cylinder wall and prevent piston slack and also provide for pistons of considerably less diameter than the diameter of the cylinder in which they are to be used.

A piston constructed in this manner may be very cheaply machined and formed to an accurate diameter, the inwardly extending ears which are integral with the piston skirt and free ends of the tongues, providing means whereby these tongues are held depressed during the turning of the exterior surface of the piston to the exact diameter, and may then be readily released by the removal of the pins. Cheapness of construction, accuracy 1 in machining, and facility of manufacture are thus secured through the present construction of piston.

Having thus fully described my invention what I claim is:

1. A piston including a skirt portion formed with outwardly yielding tongues integral with the skirt at one end and with said tongues extending in a direction at right an gles to the skirt axis, means adjacent the free end of each tongue for detachably holding said tongue with its free end depressed inwardly, said means comprising a removable pin extending transversely of the free end portion of each tongue and with said pin extending parallel with the skirt axis to engage said piston at points above and below said tongue end.

2. A piston having a head portion and a depending skirt portion, said skirtportion being formed with inwardly projecting portions at opposite sides 01" the skirt, said skirt being slitted along transverse lines with the transverse slits connected by alongitudinal slit at one end to form yielding tongues, the transverse slits dividing the inwardly projecting portions on the skirt to form adjacent ears projecting inwardly from the skirt and from said tongues adjacent their free ends and at both upper and lower edges th eof, said ears beingformed with openings to receive freely removable pins for holding the free ends of the tongues against yielding inwardly when the pins arein place. V

3. A piston comprising a head portion formed with grooves for packing ringsand gage the apertured ears, said pins extending longitudinally of the piston across the tree ends of said tongues and freely removable endwise from said apertures to release said tongues.

In testimony whereof I afiix my signature.

EMIL KorTUsor-i.

liiil 

